Butterfly the chicken breasts. Place each breast on a cutting board. Hold a knife parallel to the board and slice through the thickest part to open it like a book.
This helps the chicken cook evenly and stay juicy.
Make the jerk marinade. In a bowl, mix olive oil, lime juice, brown sugar, allspice, garlic powder, onion powder, thyme, smoked paprika, cinnamon, nutmeg, cayenne, salt, and pepper. If using Scotch bonnet or habanero, stir it in now.
Marinate the chicken. Add the chicken to a zip-top bag or shallow dish and coat with the marinade. Refrigerate for at least 30 minutes and up to 6 hours.
Longer isn’t better here; acids can toughen the meat.
Make the pineapple salsa. Combine pineapple, red onion, jalapeño, cilantro, lime zest, lime juice, and salt. Stir gently and taste. Add a little more lime or salt if needed.
Chill while the chicken cooks.
Choose your cooking method. You can grill, pan-sear, or roast: Grill: Preheat to medium-high and oil the grates. Grill 4–6 minutes per side, until the internal temperature hits 165°F.
Pan-sear: Heat 1 tablespoon oil in a skillet over medium-high. Cook 4–6 minutes per side.
Lower heat if spices begin to burn.
Oven: Preheat to 425°F. Place chicken on a lined sheet pan and roast 12–16 minutes, turning once, until cooked through.
Rest the chicken. Transfer to a plate and let it rest 5 minutes. This keeps the juices inside.
Serve. Slice the chicken against the grain.
Top with a generous spoonful of pineapple salsa. Add rice, veggies, and lime wedges if you like.